著者

中島 暉 横山 秀克 大矢 博昭 鎌田 仁

出版者

日本医学館

雑誌

磁気共鳴と医学

巻号頁・発行日

vol.12, pp.80-83, 2001

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The copper accumulation by various microorganisms were examined. Of microorganisms tested, Arthrobacter nicotianae IAM 12342 (603 ?mol/g cells), Micrococcus luteus IAM 1056 (529 ?mol/g cells), Streptomyces flavoviridis HUT 6147 (499 ?mol/g cells), Streptomyces levoris HUT###6156 (551 ?mol/g cells) have high abilities to accumulate copper. Copper accumulation by###bacterial cells was so rapid, and was affected by the pH of the solution. The ESR spectra of Cu(II) ion taken up in microbial cells were axial type, having a major absorption to higher field at g⊥ and lesser absorption to lower field at g// with four lines. The ESR parameters, g// and |A//|,###of these spectra were in the ranges of 2.238~2.303 and 15.6~18.5 mcm-1, respectively. The ESR spectra of Cu(II) in Arthrobacter nicotianae and Rhizopus oryzae cells were the superposition of two types of signals (A: g// = 2.245~2.252, |A//| = 17.6~18.2 mcm-1 and B: g// = 2.285~2.289, |A//| = 15.6~15.9 mcm-1). A new signal, g// = 2.388, |A//| = 13.0 mcm-1, was observed in Arthrobacter nictianae cells at pH 2~3. The relationship between g// and |A//| of###Cu(II) in microbial cells are almost linear, which is a similar manner as that of Cu(II)- glycyl-glycylglycylglycine in a series of pH values. These results suggested that Cu(II) in microbial cells were in the similar axial type coordination circum-stances with nitrogen and oxygen donors as those of type II Cu-proteins, and that donor atoms of Cu(II) in microbial cells were altered from 4N (higher pH) to 4O (lower pH) according to the pH variation of their coordination abilities.